Electric air heater



1952 M. H. WINNER, JR 2,580,634

ELECTRIC AIR HEATER Filed Oct. 4, 1949 2 SHEETS-SHEET 1 INS-.1-

TEA

INVENTOR.

ATTORNEYS Patented Jan. 1, IQSZ UNITED STATES PATENT OFFICE 2,580,634 ELECT-RIC AIR HEATER Mark H. Winner, Jr., New York, N. Y. Application October 4, 1949, Serial No. 119,540

3 Claims. (01. 219-49) This invention relates to heaters, and more particularly to an electric heater of the circulating-air type.

A main objectof the invention is to provide a novel and improved electric air heater which is simple in construction, compact in size, and which provides a high volume of heated air per watt of electric energy dissipated.

A further object of the invention is to provide an improved electric air heater which is inexpensive to manufacture, which is neat in appearance, which is rugged in construction, and in which thermal losses are reduced to a minimum.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein: I

Figure 1 is a side elevational view of a portable electric heater unit constructed in accordance with thepresent invention; 7

Figure 2 is a horizontal cross-sectional view taken on line. 2-2 of Figure 1;

Figure 3 is a vertical cross-sectional view taken through the heater unit of Figure 1, parts being shown broken away;

Figure 4 is a vertical cross-sectional view taken on line 4-4 of Figure 3;

Figure 5 is a top plan view of the electric heater unit shown in Figure 1;

Figure 6 is an enlarged cross-sectional detail view taken through the lower U-bend of the heater air duct on the line 5-6 of Figure 2;

Figure 6a is an enlarged fragmentary detail cross-sectional view showing a portion of the air duct and illustrating a layer of insulation which may be employed on the outer surface thereof;

Figure 7 is an enlarged fragmentary detail cross-sectional view taken through one of the upper ends of the air ducts of Figure 6 in the plane of the duct, said view illustrating the manner of housing the electrical leads of the heating coll employed in the duct;

Figure 8 is a fragmentary perspective view of one end of the U-shaped duct of Figure 6.

Referring to the drawings, 1 I designates a generally rectangular housing, which may be made of sheet metal or the like, the housing being provided with corner feet l2 which maintain the bottom wall of the housing in elevated position above the floor. Designated at I3 is an air intake duct secured to the bottom wall of the housing and opening into the space beneath the housing. Secured by suitable brackets, not

2 shown, in the duct 13 is an electric blower I4 arranged to draw air into the duct from the space beneath the housing.

As shown in Figures 3 and 4, the top portion of intake duct 13 tapers upwardly, and connected to the top end of said duct is one end of an inverted U-shaped or connecting duct 15 making substantially a ISO-degree bend. Connected to the other end of duct i5 is one end of a U-shaped or second connecting duct 16, also making substantially a -degree bend, as shown in Figures 3 and 4. Connected to the other end of duct [6 is the lower end of an outlet duct H, which has an upwardly-flaring top portion connected to an outlet grille l8 secured in the top wall of housing ll.

The inner surfaces of the respective ducts I3, [5, l6 and I! are preferably highly polished and more preferably. nickel or chromium plated, whereby said surfaces have high reflectivity to radiant energy. Therefore,the ducts absorb only a relatively small amount of radiant heat and reflect most of the radiant heat impinging thereon. As will be subsequently pointed out. the ducts, and particularly duct l6, act as a shielding means to prevent loss of radiant heat from the heat source of the unit.

The respective ducts may be provided with a suitable outer coating of heat-insulating material, such as glass wool or the like, indicated at l 9, to minimize external heat loss from the ducts by conduction and convection.

As shown in Figures 6, 7 and 8, the duct 16 has the annular flanged collars 28, 20 secured to its ends for making connection to the similarlyfianged ends of the ducts I5 and I1. Secured inside the ends of the duct iii are the radial tubular members 2 l, 2| and secured to the free ends of the tubular members 2|, 2| are the respective sleeves 22, 22. The sleeves 22 extend at right angles to the tubular members 2| and are located axially of the conduit 16. Secured in the sleeves 22 are the respective ends of a semi-circular glass tube 23 extending axially through the duct "5. As shown in Figure 7 set screws 24 are threaded through the sleeves 2'2 and enter apertures 25 in the end portions of the glass tube 23, thereby rigidly supporting the glass tube in axial posi tion in conduit I6. Designated at 26 is a helical heating coil wound helically on tube 23. Respective lead wires, shown at 21 and 28, are connected to the ends of the heating coil and extend inwardly through the ends of the glass tube, the tubular member 2|, the inner portions of the wall of duct 16 and the flanges of collars 20, as shown in Figures 6 and 7. The lead wires 21 and 28 may be connected through a switch 29 carried by the top wall of housing H to a suitable source of current.

In operation, air is drawn into the intake duct [3 by the blower unit M and passes through duct l5 to duct 16, wherein the air is heated by conduction by contact with the heater winding 26. The heated air passes upwardly through duct l1 and is discharged. from the top of housing H.

ductsuis also given upto the moving. air current by conduction.

Since the heat loss fromthe. system..is mini-- mized by the aforesaid reflective surfaces, a larger hourly volume: .of air may: be forced. through the ducts. and heated to. a desired. tem--; perature per: wattof electric power dissipatedin winding 26 than would 'be. obtainable if said reflective surfaces were not employed. Therefore,

the heater .has. a. relatively high air-heating; capacity, whereas its overall size. and-its wattage: may be relatively .small.

Whilea specific embodiment ofa portableielec-- tric air heater has been disclosed. in the: foregoingdescription, it willbe understood thatvari ous modifications within the spirit. of the: inventon may occur to those skilled in the art. Therefore, it is intended that. no limitations be. placed. on the. invention except as defined by. the. scope ofthe appended. claims.

What. is claimed is:

1.. A heater comprising a housing, an'in'letxduct;

at the bottom of the housing, an. outlet. duct at;

the upper portion of the housing, a curved duct in said? housing connecting said inlet ductito' said outlet duet,.said curved duct comprising an. inverted U-shaped duct member making a 'l80-d'e.-- greesben'd; and-sari upright. U-shaped .duct memher also making a 180-degree bend, the U-shaped duct members being joined together at their. inner. ends and said u-shaped members being highly polished on their inner surfaces, a core element secured axially in one of said U-shaped duct members, an electrical heating coil carried on said core element, and blower means in said inlet duct.

2. A heater comprising a housing, an inlet duct at the bottom of the housing, an outlet duct at the upper portion of the housing, a curved duct in said housing connecting said inlet duct to said outlet duct, said: curved duct comprising an inverted U-shaped duct member making a lBO-degree bend, and an upright U-shaped duct member also making a ISO-degree bend, the U-shaped duct-members being joined together at their inner ends, a core element secured axially in one of said U-shaped duct members, an electrical heatingcoil carried. on said core element, and blower means in one of the ducts.

3. A heater comprising a housing, a vertically disposed inlet duct positioned within said housing and having its lower end secured to. the bottom positioned within said housing inside by side spaced relation with respectto said inletductland.

having. its upper endsuppor-tedinthe top of. said housing :and in communication with the atmosphere, a first vertically disposedconneoting. duct.

positioned withinnsa-id housing. and having one end connected to the. upper. end'of saidinlet duct, a second vertically disposed connecting ductpositioned withinsaid housing and having one end connected to the other end of. said first connectin;- duct and having the other end connected to I the lower end. of said outlet duct, a core element secured axially in. one of said connecting ducts, an electrical heating coil carried. onsaid core element, and blower meansinone of said inlet and outlet. ducts.

MARK H. WINNER,..JR.

REFERENCES CITED The following references are of record in the file. of this patent:

UNITED STATES PATENTS Number. Name Date 1,001,656 Lininger et al Aug; 29,1911 1,545,079 Barlow July 7,1925 1,563,562 Gasser Dec, 1, .1925 1,829,765 Spalding Nov. 3, .1931 

